The invention relates to a device for forming an image which is composed of a plurality of sub-areas, with a detector which includes a plurality of sensor elements for generating image data and read-out units which are associated with the sub-areas of the image. The invention relates to a method of forming an image which is composed of a plurality of sub-areas, with each sub-area there being associated a respective read-out unit and image data of adjoining image areas of neighboring sub-areas being evaluated in order to mitigate differences in amplification characteristics. The invention also relates to a radiation examination device for performing the method according to the invention which includes a radiation source and a detector device with an appropriate device for carrying out the method. The invention also relates to a computerprogramm for the correction of image data of an image which is composed of a plurality of sub-areas.
Methods and devices of this kind are used, for example in image generating devices of X-ray or other radiation examination devices.
WO 96/19893 discloses an image pick-up apparatus in which an image signal is decomposed into a plurality of sub-images. More specifically, the image signal is decomposed into two sub-images which are applied to respective detector fields. An overall image signal is formed from these sub-images again in a combination unit. A correction unit is provided so as to correct differences in the sub-images. To this end, brightness values of columns of a first sub-image are multiplied by a column amplification factor and brightness values of rows of a second sub-image are multiplied by a row amplification factor. The amplification factors are derived from reference images and are stored in a memory.
For most fields of application of said methods and devices, notably for medical X-ray detectors but also for ultrasound apparatus, computed tomography apparatus or magnetic resonance apparatus, it is very important that the images formed are artefact-free to a high degree. Medical images are commonly reproduced as grey scale images. For example, X-ray and ultrasound apparatus or computed tomography or magnetic resonance tomography apparatus are used to form such grey scale images.